掺氟锂钒氧化物的电化学性能

Electrochemical Performance of the Fluorine Ion Doped Lithium Vanadium Oxides

采用固相合成法,在400℃合成了掺氟质量分数分别为0.059%、0.19%、0.35%和0.56%的系列修饰锂钒氧化物。结果表明,掺氟降低了锂钒氧化物中钒的平均价态。掺氟质量分数为0.19%的锂钒氧化物具有单斜L i1.2V3O8类型结构,最大放电容量为272 mA.h/g,40循环的容量衰减率为16%,表现出较好的电化学性能。经热分析、XRD和拉曼光谱测试分析表明,掺氟稳定了样品的晶相结构。

Via the solid-phase synthesizing method, a series of fluorine ion doped lithium vanadium oxides with the fluorine contents of 0. 059% , 0. 19% , 0. 35% and 0. 56% （mass fraction） was synthesized at 400℃, respectively. The experimental results show that the oxidation state of the vanadium of the fluorine ion doped lithium vanadium oxides is decreased with the increase of fluorine content in the samples and the doped lithium vanadium oxide with a fluorine content of 0. 19% （mass fraction） shows a monoclinic structure of Li1.2V3O8 and exhibits a max capacity of 272 mA · h/g and has a capacity fading rate of 16% in 40 cycles. Thermal analysis, XRD and Raman analysis showed that the fluorine dopant can stabilize the crystal structure of lithium vanadium oxides.